Sensitive force detection can be used in a variety of applications ranging from atomic force microscopy [33,34], biomolecule sensing [35], to motion monitoring/stabilization in automotive industry and consumer electronics [36, 37]. Current techniques are based upon micro-/nano-electromechanical systems (MEMS/NEMS) which, however, suffer from a tradeoff between sensing resolution, detection sensitivity and operation bandwidth, primarily resulting from the fundamental mechanical and electrical thermal fluctuations [38-43]. Suppression of these noise sources may need sophisticated electronics and a cryogenic environment [44-51]. Electromechanical control of microcavities have been shown previously in one-dimensional zipper and double-membrane cavities [24, 25, 26]. These approaches, however, were either limited by low tuning speed, high leakage currents, or the use of low-Q cavities, which prohibited the observation of radiation back-action effects.